There has recently been in widespread use a flat tire repair kit which, when a pneumatic tire (hereinafter simply called the “tire”) goes flat, injects a flat tire sealant into the flat tire, fills the flat tire sealant into a puncture hole, and then increases the pressure in the tire to a predetermined specified pressure. The use of such a flat tire repair kit eliminates the need to mount a spare tire on a vehicle, thereby enabling resource saving and vehicle weight saving. There is also an advantage that a space provided in the vehicle to mount the spare tire can be effectively used for other purposes.
FIG. 18 illustrates a conventional flat tire repair kit. In this flat tire repair kit, a pressure tight container 1 for storing a flat tire sealant is provided with an air inflow section 3 and a sealant discharge section 4, and hoses 12a and 12b are connected to the air inflow section 3 and the sealant discharge section 4, respectively. Compressed air is supplied to the hose 12a from a compressor C and is injected under pressure into the container 1 through the air inflow section 3. The pressure of the compressed air pushes the flat tire sealant in the container 1 out into the sealant discharge section 4, thereby injecting the flat tire sealant into a tire T through the hose 12b. 
In the flat tire repair kit described above, the container 1 needs to be secured in such a stable position that the container 1 may not fall or lean while the flat tire sealant is supplied to the tire. As a conventional countermeasure therefor, Japanese patent application Kokai publication No. 2005-39126 describes that multiple legs extending in a radial fashion are provided to a lower end of a cap attached to a lower part of a container for storing a sealant.
The legs as described above enable the container to be stably placed on a level road surface. On an inclined road surface, a rough road and the like, however, the legs have a problem that the container may turn over, for example, and thus cannot be stably placed.